trace-cmd-snapshot(1) — Linux manual page

TRACE-CMD-SNAPSHOT(1)                              TRACE-CMD-SNAPSHOT(1)

NAME         top

       trace-cmd-snapshot - take, reset, free, or show a Ftrace kernel
       snapshot

SYNOPSIS         top

       trace-cmd snapshot [OPTIONS]

DESCRIPTION         top

       The trace-cmd(1) snapshot controls or displays the Ftrace Linux
       kernel snapshot feature (if the kernel supports it). This is
       useful to "freeze" an instance of a live trace but without
       stopping the trace.

            trace-cmd start -p function
            trace-cmd snapshot -s
            trace-cmd snapshot
           [ dumps the content of buffer at 'trace-cmd snapshot -s' ]
            trace-cmd snapshot -s
            trace-cmd snapshot
           [ dumps the new content of the buffer at the last -s operation ]

OPTIONS         top

       -s
           Take a snapshot of the currently running buffer.

       -r
           Clear out the buffer.

       -f
           Free the snapshot buffer. The buffer takes up memory inside
           the kernel. It is best to free it when not in use. The first
           -s operation will allocate it if it is not already allocated.

       -c cpu
           Operate on a per cpu snapshot (may not be fully supported by
           all kernels)

       -B buf
           If a buffer instance was created, then the -B option will
           operate on the snapshot within the buffer.

SEE ALSO         top

       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1),
       trace-cmd-start(1), trace-cmd-extract(1), trace-cmd-reset(1),
       trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1)

AUTHOR         top

       Written by Steven Rostedt, <rostedt@goodmis.org[1]>

RESOURCES         top

       git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git

COPYING         top

       Copyright (C) 2010 Red Hat, Inc. Free use of this software is
       granted under the terms of the GNU Public License (GPL).

NOTES         top

        1. rostedt@goodmis.org
           mailto:rostedt@goodmis.org

COLOPHON         top

       This page is part of the trace-cmd (a front-end for Ftrace)
       project.  Information about the project can be found at [unknown
       -- if you know, please contact man-pages@man7.org] If you have a
       bug report for this manual page, send it to Steven Rostedt
       <rostedt@goodmis.org>.  This page was obtained from the project's
       upstream Git repository
       ⟨git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git⟩
       on 2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-20.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

                               05/27/2020          TRACE-CMD-SNAPSHOT(1)

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